Crops such as corn, cotton, soybeans and the like are planted in rows, at least partly to make the elimination of weeds and the harvesting easier. In general, the rows should be parallel and without sharp deviation in curvature.
Formerly, planting and cultivating was done with relatively small implements so that following the rows and staying parallel was relatively easy. Two rows or four rows were planted or cultivated by a single implement, and markers were easy to follow. End rows were narrow because the equipment could turn in a relative short radius.
However, with the advent of larger tractors and implements that plant and cultivate eight to sixteen or twenty-four rows in a single pass, the problems becomes apparent. That is particularly true of an implement having a longer tongue and being pulled by a tractor. Such implements extend a substantial distance behind the tractor so that the implement does not precisely track the tractor particularly on sharper turns. Similarly, where planting and harvesting were done by equipment covering different numbers of rows, there is an increasing need for relatively exact following of the rows by the implement.
With a mounted implement beneath or in front of the tractor, there is little or no problem. For an implement attached to a three-point hitch at the rear of the tractor, there are now mechanisms to follow a track--usually a grove--in the ground and which will then slightly adjust the track of the implement.
With the present invention, a similar device combined with the implement tongue provides for the adjustment of the track of a pulled implement. The mechanism which adjusts the track adequate for the implement on a three joint hitch must, however, be coupled as close to the operating parts of the implement as possible so that the adjustment takes place at the implement and not at the end of the tongue. Adjustment to the tongue end is so remote from the operating parts as to be substantially ineffective for possibly even counter effective. By the present invention that discovery is put into practice.